Telephone system.



F. V. YOUNG.

TELEPHONE SYSTEM.

APPLICATION FILED JUNE 19, 1914,

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aan Errea EEEEEEICK vEsiaasIaN YOUNG, or LvNDnUEsr, NEWJEEsEY, AssIGNOn To WESTERN ELECTRIC COMPANY, or NEW YORK, N. Y., A Conronarioiv or ILLINOIS.

TELEPHONE SYSTEM.

Specicaton of Letters Patent.

lPatentedlFeb. 196, 1915.

Application filed June 19, 1914. Serial No. 8463082.

To all fr0/0m t may concern Be it known that I, FREDERICK V. YOUNG, a citizen of the United States, residing at Lyndhurst, in the county of Essex andfState of New Jersey, have invented certain new and useful Improvements in Telephone Systems, of which the `following is a full, clear, concise, and `exact description.

This invention relates to telephone systems, and `more particularly to such systems of the central energy type 'in which there may be one `or more stations connected -to a single line.

The Object of this invention is the production of improved signal-controlling mea-ns for such systems.

in accordance with this invention there is lprovided `an electromagnetic means for automatically removing the ringing current from the line, and connecting an operators telephone set therewith when a called `.party removes the receiver from the switch hook. Said electromagnetic means may comprise a relay having a ipl-urality of windings, one of which is normally short-circuited-throngh a contact of a second relay. rlhe removal of a receiver from a switch hook operates said second relay, which removes the short, permits the rst mentioned relay to operate, disconnecting the ringing current, `and connecting the operators telephone set to the line.

The accompanying1 drawing illustrates diagrammatically one of the arrangements by which this invention may be etfectuated.

ln the drawing there is shown a telephone line terminating in a switchboard located at a central office. The switchboard .is provided with an ordinary standard operators set A, which is normally connected, through the Contact of an operating key B, to a telephone line. yThis connection may be traced by the following path: starting from Contact 40 of the operating key B, line wire 1, through the various substations C, D and E, back over line wire 2, contact 38, conductors 16, 4, through the operators set A, conductors 3, 18, back to Contact 40. The manner of signaling central is the same as is customarily employed in signaling central in the ordinary common battery system. In event a party wishes to call central from one of the substations C, upon removing the receiver from the switch hook the line relay 8 is energized. The energization of line relay8 closes contact 13, which completes a circuit through the line lamp 14, causing said lamp to be lighted.

,Vl/'hen the central operator wishes to ring one l of the substations, ringing current is applied to the line by actuating the operating key B. rl`he actuation of the key B closes contacts 37, 39 and 41. The closing of contact 39 causes the energization of relay 7 by completing Ithe following circuit: battery 10, conductor 20, contact 39, conductor 17, through one of the windings of relay 5, conductor 25, contact 83, conductors 27, 21, through the coil of relay 7, back to battery. It may be stated `here that relay 5 is comprised of two windings, one of which is normally short-circuited. The current whichflows through the other winding is not sufficient to energize the relay 5, but is sufficient to cause said relay tobe saturated so that it is rendered sensitive to a small amount of additional current. Therefore, whenever the short is removed from the winding normally short-circuited, the relay 5 immediately pulls up.

rlhe energization of relay 7 over the path just described closes contact 36. rlhis causes ringing current to be sent over the line wires 1 and 2 by closing the following circuit: from battery 11, through the generator 12, conductor 23, back contact 32 of relay 5, conductor 15, contact 37, line wire 2,through coil of relay 9, line wire 1, contact 41, conductor 19, back contact 35 of relay 5, conductor 26, coil of relay 6, conductor 22, contact 36, back to battery 11. Relay 9 is of a type which is responsive to alternating current, while relay 6 is only energized by direct current. Consequently, relay 9 will be energized by the ringing current sent over the line, closing Contact 45. The elo-- sure of contact .45 completes a circuit through the lamp 46, causing it to be lighted. The ringing current fiowing from the generator 12 will operate the signal 42. `We thus have two means for attracting the attention of the individuals at the various substations.

Since relay 6, as mentioned above. is only responsive to direct current, it will not be energized at the time ringing current is applied to the line wires 1 and 2 over the circuit just described. However, when the receiver is removed from the switch hook at substation C, a circuit is completed which permits the How of direct current, and results in the energizvation of relay 6. The actuation of relay 6 removes the short from the winding oi relay. 5 that is normally short-circuited by opening contact 33. The two windings of relay 5 are now cut in series, and current sui'licient te energize said relay flows through the following path:

battery 10, conductor 20, contact 39, conductor 17, both windings of relay 5, conductors 28, 21, the coil of relay 7, back to battery. rI`he energization of relay 5 removes the ringing current by 'opening contacts 32 and 35, whilethe closing of contacts 31 and 34 connects the operators set A to the line wires 1 and 2 by establishing the following circuit: starting from contact 41 of lthe operating key B, line wire 1, through the substation C, line wire 2, contact 37, conductor 15front contact 31 of relay 5, conductors 29, 4, through the operator-s set A, conductors 3, 30, front contact 34 of relay i 5, conductor 19,'back to contact 41. The

opening of Contact 35 at the time the relay 5 is energized, breaks the circuit through relay 6, causing its denergization and the consequent closing of contact 33, which in turn short-cireuits the normally short-circuited winding of relay 5.- By restoring the operating key B to normal position, current may be removed from relays 5, 6 and 7, and at thesame time a circuit i'or conversational purposes will still be maintained between the substation C and the operators set A, since, as described above, the loperators telephone set is normallyvconnected to the telephone line.

From the above description it will be seen that the application of ringing current to a subscribers line is automatically controlled by an electromagnetic device which responds immediately wheny a called subscriber removes the receiver from the switch hook.

What is claimed is:

1. A telephone system comprising a central otiice, a telephone line terminating thereat, an operators telephone set normally connected to said line, a source of ringing current, switching means for disconnecting said operators telephone set from said line and connecting thereto said source of ring- 'ing current, and electromagnetic means operated upon response of the called party to disconnect said source of ringing current from said line and connect therewith said operators telephone set.

Copies of this patent may be obtained for 2. A telephone system comprising a central oiiiee, a telephone line terminating thereat, an operators telephone setnormally connected to said line, a source of ringing current, switching means for disconnecting said operators telephone set from said line and connecting thereto said source of ringing current, and an electromagnetic device for automatically disconnecting saidl ringing current from said line and connecting said operators telephone set therewith, said electromagnetic device having a plurality of: windings, one oi which is normally shortcircuited.

3. A telephone system comprising a ccntral oiiice, a telephone line terminating thereat, an operators telephone set normally connected to said line, a source ci ringing current, switching means for disconnecting said operators telephone set :trom said line and connecting thereto said source of ringing current, an electromagnetic device having a plurality of windings, one of which is normally short-circuited, and means actuated upon the removal of' a receiver from a switch hook for removing the short from said normally short-circuited winding, whereby said electromagnetic device is actuated to disconnect said ringing current from said line and connect said operators telephone set therewith.

4. A telephone system comprising a central oiiice, a telephone line terminating thereat, an operators telephone set, sources of ringing current and direct current at said central oi'lice, a relay at said central oilicc having a plurality of windings, switching means for completing a local circuit including a winding-of said relay and said source of direct current and for connecting said source of ringing current to said line, and means at said central oliice actuated upon removal of a receiver from a switch hook to include another winding of said relay in said local circuit, whereby said relay is operated to disconnect said source of ringing current from saidline and connect said operators telephone set therewith.

In witness whereof, I hereunto subscribe my name this 17th day of June A. D., 1914.

FREDERICK VESIASIAN YOUNG.

Witnesses:

KATHERINE L. STAHL, E. EDLER.

ve cents each, by addressing the Commissioner of Eatents,

Washington, D. C. 

